Biology of Bisexuality

In the last issue we discussed the basic concepts and hypotheses about bisexuality and how ideas concerning the subject evolved throughout time. The discovery that the genital system in both sexes had a common origin boosted the speculation that the human mind was essentially bisexual. But substantial evidence was lacking. The ball shifted to the court of neuropsychologists to furnish the much needed evidence.

The first attempts in this direction were made by Kiernan (1884, 1888), Frank Lydston (1889, [892), and the Frenchman Chevalier (1893). The works of these scientists prompted a Viennese psychologist to further study the subject. He came up with a theory

“since the peripheral part of the sexual apparatus is of bisexual predisposition, this must be true of the central part as well. Thus one must assume that the cerebrum contains male and female centres whose antagonistic action and relative strength determine the individual’s sex behaviour.The central part of the sex system is autonomous and therefore independently subject to developmental disturbances.”

But he could not provide any shred of evidence for his assumptions.

This dominant theory of bisexuality began to wither away as increasing biological evidences began surfacing. Research into the psychological aspects of man’s sexuality gained momentum and also underwent a paradigm shift of approach. Anatomy was gradually replaced with functional attributes. The developments have been summarised by Frank R Lillie in his works:

“There is no such biological entity as sex. What exists in nature is a dimorphism within species into male and female individuals, which differ in respect to contrasting characters; it is merely a name for our total impression of the differences. It is difficult to divest ourselves of the pre-scientific anthropomorphism which assigned phenomena to the control of personal agencies, and we have been particularly slow in the field of the scientific study of sex characteristics in divesting ourselves not only of the terminology but also of the influence of such ideas. . . . Sex of the gametes and sex in bodily structure or expression are two radically different things. The failure to recognize this elementary principle is responsible for much unsound generalization.“

What his peers and scientists concluded from his findings is an interesting definition of sex (or in modern terminology sexuality). Sex cannot be solely determined by the type of gonads one possesses. It would be erroneous to ascertain “male” or “female” character to someone based on the levels of hormones in their blood stream. It can only be determined by the reproductive action of the system as whole and not a few tissue systems. The flip side to this theory is that reproductive maturity is a pre requisite of reproductive action. Hence, the sexuality of infant or for that matter zygote cannot be ascertained. The possible answer to this riddle is the fact that zygote in early stages of development has the ability to give rise to male or female individual depending on the genetic or endocrine factors present. So it can essentially be considered bisexual.

Thus an interesting definition of sexuality was emerging. In the next issue we shall i shall take this discussion forward, elaborating the problems faced by psychoanalysts. Till then happy reading.

[This article was first published in Gaylaxy magazine. You can read Gaylaxyonline here.]